A triboelectric nanogenerator and its preparation method

Abstract

The present invention provides a triboelectric nanogenerator and a method for preparing the same, relating to the field of triboelectric nanogenerator technology. The method comprises: simultaneously performing electrospinning and electrostatic spraying, wherein the electrostatic spraying material comprises a highly electronegative nanomaterial, such as polytetrafluoroethylene nanoparticles and polyperfluoroethylene propylene nanomaterials. The present invention utilizes a blending technique to simultaneously perform electrospinning and electrostatic spraying of the highly electronegative nanomaterial, resulting in a one-step, efficient preparation of an electrospun composite membrane. Furthermore, by using a high-voltage negative electrode to spray the highly electronegative nanoparticles, the present invention achieves corona polarization, allowing the electrostatically sprayed highly electronegative material to carry more negative charge, thereby improving the electrical properties of the composite membrane.

Description

Technical Field

[0001] The present invention relates to the technical field of triboelectric nanogenerator, and in particular to a triboelectric nanogenerator and a preparation method thereof. Background Art

[0002] Flexible electronics have a wide range of potential applications in health monitoring and smart wearable devices due to their lightweight, high-performance, and excellent fit to human skin. Compared to most current capacitive and resistive wearable sensors that require a power source, triboelectric nanogenerators based on triboelectric charging and electrostatic induction effects offer significant advantages in electronic skin and energy harvesting because they do not require a power source. The triboelectric negative electrode material plays a crucial role in triboelectric nanogenerators. However, currently used materials with high electronegativity, such as PTFE (polytetrafluoroethylene) or FEP (perfluoroethylene propylene copolymer), are relatively rigid and therefore have poor stretchability. Elastomers with good stretchability, such as PDMS and silicone, have relatively low electronegativity, making it difficult to prepare high-performance tensile strain-type triboelectric nanogenerators, and the preparation process is complex. Summary of the Invention

[0003] The problem solved by the present invention is that most of the current tensile-type friction nanogenerators have defects such as poor tensile strain performance or poor power generation performance, making it difficult to prepare high-performance, high-tensile strain friction nanogenerators.

[0004] To solve at least one of the above problems, the present invention provides a method for preparing a triboelectric nanogenerator, comprising:

[0005] A spinning solution, a first spray dispersion, and a second spray dispersion are separately prepared, wherein the first spray dispersion is obtained by mixing a highly electronegative nanomaterial with a dispersion solution and dispersing the mixture through stirring, wherein the highly electronegative nanomaterial comprises one of polytetrafluoroethylene nanoparticles and polyperfluoroethylene propylene nanomaterials; and the second spray dispersion is obtained by dispersing silver nanowires in ethanol;

[0006] The spinning solution and the first spray dispersion are connected to the negative high-voltage end respectively, and the receiving roller is connected to the positive high-voltage end, and electrostatic spinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously to produce a first composite spinning membrane;

[0007] The spinning solution and the second spray dispersion are connected to the positive high-voltage end respectively, and the receiving roller is connected to the negative high-voltage end, and electrostatic spinning and electrostatic spraying of silver nanowires are performed simultaneously to prepare a second composite spinning membrane;

[0008] The first composite spinning membrane and the second composite spinning membrane are laminated together, and a conductive electrode is connected to the second composite spinning membrane to obtain a triboelectric nanogenerator.

[0009] Preferably, the spinning solution is obtained by adding spinning masterbatch into a dispersion and magnetically stirring at room temperature for 5-8 hours, wherein the spinning masterbatch comprises one of TPU particles, polylactic acid, nylon and polyvinyl alcohol.

[0010] Preferably, the mass percentage of the spinning masterbatch in the spinning solution is 4-6%.

[0011] Preferably, the mixing of the highly electronegative nanomaterial with the dispersion solution and the dispersion by stirring comprises: adding the highly electronegative nanomaterial to the dispersion solution, adding a magnetic stirrer, sealing the solution, ultrasonically dispersing the solution at room temperature for 1 hour, and then magnetically stirring the solution for 2 hours to obtain the first spray dispersion.

[0012] Preferably, when electrospinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously, the electrospinning parameters include: boost speed of 0.02-0.08 ml / min, translation speed of 60-100 mm / min, spinning temperature of 40°C, humidity of 30%, and time of 3-7 h.

[0013] Preferably, when the electrospinning and the electrostatic spraying of the highly electronegative nanomaterial are performed simultaneously, the rotation speed of the receiving drum is 50-150 rpm, the voltage value of the positive high-voltage end is 2kV, and the voltage value of the negative high-voltage end is 9kV.

[0014] Preferably, when electrospinning and electrostatic spraying of silver nanowires are performed simultaneously, the electrospinning parameters include: boost speed of 0.02-0.08 ml / min, translation speed of 60-100 mm / min, spinning temperature of 40°C, humidity of 30%, and time of 3-7 h.

[0015] Preferably, when the electrospinning and the electrostatic spraying of the silver nanowires are performed simultaneously, the rotation speed of the receiving roller is 50-150 rpm, the voltage value of the negative high-voltage end is 2 kV, and the voltage value of the positive high-voltage end is 9 kV.

[0016] Preferably, laminating the first composite spinning membrane and the second composite spinning membrane together and connecting a conductive electrode to the second composite spinning membrane comprises:

[0017] The first composite spinning membrane and the second composite spinning membrane are bonded together with VHB double-sided adhesive tape, and copper wires and silver paste are used to lead out from the second composite spinning membrane as conductive electrodes.

[0018] The advantages of the preparation method of the present invention over the prior art are:

[0019] This invention utilizes a blending technique to simultaneously perform electrospinning and electrostatic spraying of highly electronegative nanomaterials, resulting in a highly efficient, one-step process for preparing electrospun composite membranes. Furthermore, by using a high-voltage cathode to spray highly electronegative nanoparticles, the invention achieves corona polarization, allowing the electrostatically sprayed highly electronegative materials to carry more negative charge, thereby improving the electrical properties of the composite membrane. Furthermore, the composite membrane structure prepared by this invention effectively prevents the shedding of highly electronegative nanomaterials during stretching or deformation, thereby enhancing the durability and stability of the triboelectric nanogenerator.

[0020] The present invention also provides a friction nanogenerator, which is prepared by adopting the preparation method of the friction nanogenerator.

[0021] The advantages of the triboelectric nanogenerator of the present invention over the prior art are the same as the advantages of the method for preparing the triboelectric nanogenerator over the prior art, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Flowchart of a method for preparing a triboelectric nanogenerator according to an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the blending preparation process of the friction nanogenerator in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, an embodiment of the present invention provides a method for preparing a triboelectric nanogenerator, comprising:

[0026] A spinning solution, a first spray dispersion, and a second spray dispersion are separately prepared, wherein the first spray dispersion is obtained by mixing a highly electronegative nanomaterial with a dispersion solution and dispersing the mixture through stirring, wherein the highly electronegative nanomaterial comprises one of polytetrafluoroethylene (PTFE) nanoparticles and polyperfluoroethylene propylene (FEP) nanomaterials; and the second spray dispersion is obtained by dispersing silver nanowires in ethanol;

[0027] The spinning solution and the first spray dispersion are connected to the negative high-voltage end respectively, and the receiving roller is connected to the positive high-voltage end, and electrostatic spinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously to produce a first composite spinning membrane;

[0028] The spinning solution and the second spray dispersion are connected to the positive high-voltage end respectively, and the receiving roller is connected to the negative high-voltage end, and electrostatic spinning and electrostatic spraying of silver nanowires are performed simultaneously to prepare a second composite spinning membrane;

[0029] The first composite spinning membrane and the second composite spinning membrane are laminated together, and a conductive electrode is connected to the second composite spinning membrane to obtain a triboelectric nanogenerator.

[0030] In this embodiment, a spinning solution is prepared for electrospinning to obtain a spinning membrane, and at the same time, a prepared first spray dispersion containing highly electronegative nanomaterials such as PTFE is sprayed onto the spinning membrane to obtain a composite spinning membrane, thereby preparing a composite film through a one-step in-situ mixed spinning method with high preparation efficiency. Moreover, this one-step in-situ mixed spinning method can not only uniformly compound nanoparticles such as PTFE in the spinning fiber membrane, but also effectively protect the PTFE nanoparticles fixed on the spinning fiber, so that they will not easily detach from the spinning membrane due to deformation such as stretching and bending, thereby improving the durability of the composite membrane. At the same time, since the present embodiment adopts a dual-nozzle in-situ polarization blending technology, both end nozzles are connected to a high-voltage negative electrode, one end of the nozzle is used for electrostatic spinning to prepare a spinning film, and the other end is used for high-voltage negative electrode electrostatic spraying. When using the high-voltage negative electrode to spray PTFE and other nanoparticles, when the PTFE and other nanoparticle solutions are squeezed out from the nozzle connected to the negative high voltage, under the action of the high-voltage electric field, the air near the nozzle is ionized to release electrons, so that the ejected PTFE and other nanoparticles are charged and deposited on the middle roller by electrostatic attraction. Therefore, when PTFE and other nanoparticles are sprayed on the spinning film, since the nozzle is connected to the high-voltage negative electrode, the ejected PTFE nanoparticles carry more negative charges, realizing the effect of corona polarization, thereby improving the electrical properties of the composite spinning membrane.

[0031] The output performance of the current composite membrane-type friction nanogenerator prepared based on electrospinning technology is not high enough. The main reason is the material selection. This embodiment uses nanoparticles such as PTFE with high electronegativity and utilizes the polarization effect of the high-voltage negative electrode to make the highly electronegative nanoparticles sprayed with the high-voltage negative electrode polarization carry more negative charge. When they come into contact with the positive electrode material, they can produce a greater triboelectric effect. Although the prior art also uses high-voltage polarization to improve performance, the operation process is relatively complicated and generally requires two steps, namely, preparing the material first and then high-voltage polarization. The one-step high-voltage negative electrode spraying of PTFE and other nanoparticles in this embodiment simultaneously realizes the compounding of PTFE and other nanoparticles in the fiber membrane and in-situ polarization, which further strengthens the negative charge of materials such as PTFE, thereby producing higher performance. At the same time, the electronegative material is polarized and sprayed onto the spinning membrane, and the process is carried out simultaneously with electrospinning. This allows the highly electronegative nanoparticles polarized by the high-voltage negative electrode to be firmly fixed on the spinning film, thereby improving the tensile strain performance of the spinning film, thereby solving the problem in the existing technology of difficulty in preparing high-performance, high-tensile strain friction nanogenerators.

[0032] In some embodiments, the spinning solution is prepared by adding spinning masterbatch to a dispersion at a specific ratio and magnetically stirring at room temperature for 5-8 hours. The spinning masterbatch comprises one of TPU particles, polylactic acid, nylon, and polyvinyl alcohol, and the dispersion can be a hexafluoroisopropanol solution. The mass percentage of the spinning masterbatch in the spinning solution is 4-6%.

[0033] By setting the concentration of the spinning solution within the range of 4-6% by mass of the spinning masterbatch, a uniform and dense spinning film can be obtained during high-voltage electrospinning, facilitating the uniform distribution of highly electronegative nanoparticles on the spinning film.

[0034] In some embodiments, the mixing of the highly electronegative nanomaterial with the dispersion solution and the dispersion by stirring comprises: adding the highly electronegative nanomaterial to the dispersion solution, adding a magnetic stirrer, sealing the solution, ultrasonically dispersing the solution at room temperature for 1 hour, and then magnetically stirring the solution for 2 hours to obtain the first spray dispersion.

[0035] By combining ultrasonic dispersion with magnetic dispersion, a uniform first spray dispersion is obtained after sufficient stirring and dispersion, so as to facilitate uniform spraying of nanoparticles such as PTFE on the spinning film.

[0036] In some embodiments, when electrospinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously, the parameters for electrospinning performed by the spinning machine include: a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, and a humidity of 30%. The speed of the receiving drum is 50-150 rpm, the voltage value of the positive high-voltage end is set to 2 kV, that is, the positive pressure of the receiving drum is +2 kV, and the voltage value of the negative high-voltage end is set to 9 kV, that is, the negative pressure at the spinning end is -9 kV, and the negative pressure at the spraying end is -9 kV. The thickness of the spun film is adjusted by the spinning time, and the spinning time is preferably set to 3-7 h.

[0037] In some embodiments, when performing electrospinning and electrostatic spraying of silver nanowires simultaneously, the electrospinning parameters of the spinning machine include: a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, and a humidity of 30%. The receiving drum rotates at 50-150 rpm, the negative high-voltage terminal has a voltage of 2 kV (i.e., the negative pressure on the receiving drum is set to -2 kV), and the positive high-voltage terminal has a voltage of 9 kV (i.e., the positive pressure on the spinning end is +9 kV, and the positive pressure on the spraying end is +9 kV). The thickness of the TPU film is adjusted by the spinning time, which is preferably 3-7 hours depending on the thickness.

[0038] In some embodiments, the step of laminating the first composite spinning membrane and the second composite spinning membrane together and connecting a conductive electrode to the second composite spinning membrane includes: laminating the first composite spinning membrane and the second composite spinning membrane together with VHB double-sided tape, and using copper wire and silver paste to lead out from the second composite spinning membrane as a conductive electrode, thereby obtaining a friction nanogenerator by assembling the first composite spinning membrane, the second composite spinning membrane and the conductive electrode.

[0039] Another embodiment of the present invention provides a triboelectric nanogenerator, which is manufactured using the above-mentioned manufacturing method.

[0040] The present invention is described in detail below by way of examples.

[0041] Example 1

[0042] This embodiment provides a method for preparing a triboelectric nanogenerator, which specifically includes:

[0043] Preparation of TPU solution: Add 0.8g TPU masterbatch to 19.2g hexafluoroisopropanol solution, add a magnetic stirrer, seal and stir at room temperature for 6h to obtain a TPU spinning precursor with a mass fraction of 4%. Add the spinning precursor to the needle tube used for electrospinning, such as Figure 2 Shown is the needle on the left.

[0044] Preparation of PTFE dispersion: Weigh 1g of PTFE nanoparticles according to the ratio and add it to 19g of hexafluoroisopropanol solution. Place a magnetic stirrer, seal it, and ultrasonically disperse it at room temperature for 1 hour. Then, magnetically stir it for 2 hours to obtain a 5% PTFE dispersion. Add the PTFE dispersion to the needle tube used for electrospinning, as shown in the following figure. Figure 2 Shown in the needle on the right.

[0045] Preparation of PTFE / TPU composite spinning film: Set the spinning machine parameters to a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, a humidity of 30%, and a spinning time of 3 hours. The receiving drum speed was 50-150 rpm. The positive pressure on the receiving drum was set to +2 kV, the negative pressure on the TPU spinning end was set to -9 kV, and the negative pressure on the PTFE spraying end was set to -9 kV.

[0046] Preparation of AgNWs (silver nanowire) / TPU spinning membranes: 20 mg of silver nanowires were dispersed in 20 ml of ethanol and sonicated for 30 minutes. The spinning machine parameters were set to a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, a humidity of 30%, and a spinning time of 3 hours. The receiving drum speed was set at 50-150 rpm. The negative pressure on the receiving drum was set to -2 kV, the positive pressure on the TPU spinning end was set to +9 kV, and the positive pressure on the AgNW spraying end was set to +9 kV.

[0047] Assembly: The PTFE / TPU composite spinning film and the AgNWs / TPU spinning membrane were bonded with VHB double-sided tape, and copper wires and silver paste were used to lead out from the AgNWs / TPU membrane as electrodes.

[0048] This embodiment uses a one-step in-situ polarization blending technology to prepare a TPU / PTFE composite film, achieving the rapid preparation of a high-performance, durable thin-film friction nanogenerator. This one-step in-situ blending method not only evenly composites PTFE nanoparticles within the TPU film, but also sprays high-voltage negatively polarized PTFE nanoparticles, giving them a more negative charge, thereby improving performance. In addition, the structure of the PTFE / TPU composite film prepared by blending effectively protects the PTFE nanoparticles fixed to the TPU fibers, preventing them from easily detaching due to deformation such as stretching and bending, thereby improving the durability of the composite film.

[0049] Example 2

[0050] This embodiment provides a method for preparing a triboelectric nanogenerator, which specifically includes:

[0051] Preparation of PLA solution: Add 1.2g of PLA masterbatch to 18.8g of hexafluoroisopropanol solution, place a magnetic stir bar, seal the solution, and stir at room temperature for 6 hours to obtain a 6% PLA spinning precursor. This spinning precursor is then added to the needle used for electrospinning.

[0052] Preparation of FEP dispersion: Weigh 1g of FEP nanoparticles according to the appropriate ratio and add them to 19g of hexafluoroisopropanol solution. Place a magnetic stir bar in the container, seal it, and ultrasonically disperse at room temperature for 1 hour. Then, magnetically stir for 2 hours to obtain a 5% FEP dispersion. This FEP dispersion was then added to the syringe used for electrospinning.

[0053] Preparation of FEP / PLA composite spunbond film: Set the spinning machine parameters to a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, a humidity of 30%, and a spinning time of 3 hours. The receiving drum speed was 50-150 rpm. The positive pressure on the receiving drum was set to +2 kV, the negative pressure on the PLA spinning end was set to -9 kV, and the negative pressure on the FEP spraying end was set to -9 kV.

[0054] Preparation of AgNWs (silver nanowires) / polylactic acid (PLA) spinning membranes: 20 mg of silver nanowires were dispersed in 20 ml of ethanol and sonicated for 30 minutes. The spinning machine parameters were set to a boost speed of 0.02-0.08 ml / min, a translation speed of 60-100 mm / min, a spinning temperature of 40°C, a humidity of 30%, and a spinning time of 3 hours. The receiving drum speed was set at 50-150 rpm. The negative pressure on the receiving drum was set to -2 kV, the positive pressure on the PLA spinning end was set to +9 kV, and the positive pressure on the AgNW spraying end was set to +9 kV.

[0055] Assembly: The FEP / PLA composite spinning film and the AgNWs / PLA spinning film were bonded with VHB double-sided tape, and copper wires and silver paste were used to lead out from the AgNWs / PLA film as electrodes.

[0056] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a triboelectric nanogenerator, characterized in that: include: A spinning solution, a first spray dispersion, and a second spray dispersion are separately prepared, wherein the first spray dispersion is obtained by mixing a highly electronegative nanomaterial with a dispersion solution and dispersing the mixture through stirring, wherein the highly electronegative nanomaterial comprises one of polytetrafluoroethylene nanoparticles and polyperfluoroethylene propylene nanomaterials; and the second spray dispersion is obtained by dispersing silver nanowires in ethanol; The spinning solution and the first spray dispersion are connected to the negative high-voltage end respectively, and the receiving roller is connected to the positive high-voltage end, and electrostatic spinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously to produce a first composite spinning membrane; The spinning solution and the second spray dispersion are connected to the positive high-voltage end respectively, and the receiving roller is connected to the negative high-voltage end, and electrostatic spinning and electrostatic spraying of silver nanowires are performed simultaneously to prepare a second composite spinning membrane; The first composite spinning membrane and the second composite spinning membrane are laminated together, and a conductive electrode is connected to the second composite spinning membrane to obtain a triboelectric nanogenerator.

2. The method for preparing a triboelectric nanogenerator according to claim 1, wherein: The spinning solution is obtained by adding spinning masterbatch into a dispersion and magnetically stirring at room temperature for 5-8 hours, wherein the spinning masterbatch comprises one of TPU particles, polylactic acid, nylon and polyvinyl alcohol.

3. The method for preparing a triboelectric nanogenerator according to claim 2, characterized in that: The mass percentage of the spinning masterbatch in the spinning solution is 4-6%.

4. The method for preparing a triboelectric nanogenerator according to claim 1, wherein: The mixing of the highly electronegative nanomaterial with the dispersion solution and the stirring dispersion comprises: adding the highly electronegative nanomaterial to the dispersion solution, adding a magnetic stirrer, sealing the solution, ultrasonically dispersing the solution at room temperature for 1 hour, and then magnetically stirring the solution for 2 hours to obtain the first spray dispersion.

5. The method for preparing a triboelectric nanogenerator according to claim 1, wherein: When electrospinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously, the electrospinning parameters include: boosting speed of 0.02-0.08 ml / min, translation speed of 60-100 mm / min, spinning temperature of 40° C., humidity of 30%, and time of 3-7 h.

6. The method for preparing a triboelectric nanogenerator according to claim 1, wherein: When electrospinning and electrostatic spraying of highly electronegative nanomaterials are performed simultaneously, the rotation speed of the receiving roller is 50-150 rpm, the voltage value of the positive high-voltage end is 2kV, and the voltage value of the negative high-voltage end is 9kV.

7. The method for preparing a triboelectric nanogenerator according to claim 1, characterized in that: When electrospinning and silver nanowire electrostatic spraying are performed simultaneously, the electrospinning parameters include: boost speed of 0.02-0.08 ml / min, translation speed of 60-100 mm / min, spinning temperature of 40° C., humidity of 30%, and time of 3-7 h.

8. The method for preparing a triboelectric nanogenerator according to claim 1, wherein: When electrospinning and electrostatic spraying of silver nanowires are performed simultaneously, the rotation speed of the receiving roller is 50-150 rpm, the voltage value of the negative high-voltage end is 2kV, and the voltage value of the positive high-voltage end is 9kV.

9. The method for preparing a triboelectric nanogenerator according to claim 1, characterized in that: The step of laminating the first composite spinning membrane and the second composite spinning membrane together and connecting a conductive electrode to the second composite spinning membrane comprises: The first composite spinning membrane and the second composite spinning membrane are bonded together with VHB double-sided adhesive tape, and copper wires and silver paste are used to lead out from the second composite spinning membrane as conductive electrodes.

10. A triboelectric nanogenerator, characterized in that: The triboelectric nanogenerator is prepared by the preparation method according to any one of claims 1 to 9.

Images